1. What is the ExRx 1RM Calculator?

The ExRx 1RM Calculator estimates your one-repetition maximum (1RM) based on the Brzycki formula. This is the maximum amount of weight you can lift for a single repetition of a given exercise.

2. How Does the Calculator Work?

The calculator uses the Brzycki formula:

Where:

• \( Weight \) — The amount of weight lifted
• \( Reps \) — Number of repetitions performed (1-20)

Explanation: The formula estimates your maximum capacity based on submaximal loads, with greater accuracy for repetitions between 2-10.

3. Importance of 1RM Calculation

Details: Knowing your 1RM helps in designing strength training programs, tracking progress, and setting appropriate training loads for different goals.

4. Using the Calculator

Tips: Enter the weight you lifted and how many repetitions you performed with that weight. For best results, use a weight that allows 2-10 reps before failure.

5. Frequently Asked Questions (FAQ)

Q1: Why use Brzycki formula instead of others?
A: The Brzycki formula is one of the most accurate and widely used 1RM prediction equations, especially for novice to intermediate lifters.

Q2: What are the limitations of this calculator?
A: Accuracy decreases with very high reps (>10) and doesn't account for exercise-specific factors or individual variations in fatigue resistance.

Q3: Should I actually test my 1RM?
A: For beginners, estimated 1RM is safer. Experienced lifters can test actual 1RM with proper warm-up and safety precautions.

Q4: Does this work for all exercises?
A: Best for compound lifts like bench press, squat, deadlift. Less accurate for isolation exercises or endurance-focused movements.

Q5: How often should I recalculate my 1RM?
A: Every 4-8 weeks for beginners, 8-12 weeks for intermediate lifters, as strength gains occur at different rates.